Irons consist of a sole plate which supports above it the iron body. The body includes a tank to receive water together with a valve to regulate the delivery of water from the tank to the sole plate for the purposes of generating steam. Steam is gathered in a cavity formed above the sole plate and is delivered to the fabric being ironed by passages extending through the sole plate. Frequently irons are provided with a second means of delivering water to the sole plate. This second means is generally a pump which delivers a predetermined quantity of water to the sole plate upon being manipulated by a user of the iron. A burst of steam is then delivered from the sole plate.
The temperature of the iron is governed by a thermostat which may be mounted centrally or towards the front of the iron. The user via a dial mechanism or switch operates the thermostat to regulate the temperature of the sole plate.
Previously known irons have suffered several disadvantages including the following.
Water delivered to the sole plate for the purposes of generating a constant stream of steam, tends to migrate to the cooler portions of the sole plate. This exacerbates any temperature differences which may exist across the sole plate. This problem can be still further exacerbated if the thermostat is located adjacent one of these cooler regions. The thermostat may be deceived to permit excessive current to be delivered to the heating element. In extreme circumstances it has been known for one side of the sole plate to be 100.degree. lower than the other side.
If the water delivered to the sole plate congregates at a cooler region, the operator can be deceived in thinking sufficient steam is being generated when the iron is placed in its rest position supported on its "heel". When the iron is oriented in this generally upright position the water migrates to hotter regions of the sole plate and generates more steam.
In irons where the temperature control knob is located generally centrally of the iron, it is necessary to have the thermostat spaced from the element due to the size of the thermostat. Thermostats are manufactured in set sizes which limits the distance they can be mounted from the temperature control knob. This leads to inaccuracies as the thermostat is not located adjacent the heating element. Accordingly in some instances the iron can be caused to overheat.
A still further disadvantage is the use of pumped water for the production of bursts of steam. The pumped water is delivered to a position directly on top of the heating element in order to manufacture sufficient steam. However the additional steam is not restrained and tends to distribute throughout the steam cavity (steam chest) thereby diminishing the quantity of steam delivered in the burst.